This is a genetic association study evaluating whether single nucleotide polymorphisms (SNPs) in vascular endothelial growth facotr (VEGF),erythropoietin (EPO), endothelin-1 (EDN1) and activated glycation end products (AGE) genes affect the development and progression of DME. All participants will provide a blood sample, undergo an eye examination, optical coherence tomography (OCT) and potentially fluorescein angiography (FA). They will also discuss their medical, family and social history. Case participants with DME and control participants without DME will be allowed to continue receiving conventional eye treatment at the NEI under this protocol. The primary outcome variable is the genotype frequency of SNPs in the above specific genes of DME and control participants. Secondary outcomes are serum levels of VEGF, EPO, EDN1, AGE and ophthalmic measurements (visual acuity and imaging results such as FA and OCT results). Additionally, longitudinal data about response to treatment of diabetic macular edema will be gathered to attempt to discern a genetic predictor of response to particular treatment. This protocol has been terminated.